The present invention relates to a carbon-based material and a method of producing the same, and a composite material and a method of producing the same.
A composite material using a carbon material such as a carbon fiber, carbon black, graphite, or carbon nanofiber has attracted attention (e.g. Japanese Patent Application Laid-Open No. 5-78110). Such a composite material is expected to exhibit improved electrical conductivity, heat transfer properties, mechanical strength, and the like due to inclusion of the carbon material such as the carbon nanofibers.
However, the carbon material generally exhibits low wettability (affinity) with the matrix material of the composite material, and also exhibits low dispersibility in the matrix material. In particular, since the carbon nanofibers have strong aggregating properties, it is very difficult to uniformly disperse the carbon nanofibers in the matrix of the composite material. As the surface treatment for the carbon nanofibers, wet plating, evaporation, and the like have been studied. However, since the thickness of the surface-treated layer is increased, the carbon nanofibers are bonded through the surface-treated layer. Therefore, it is difficult to obtain a carbon nanofiber composite material having desired properties. Moreover, expensive carbon nanofibers cannot be efficiently utilized.